"At 0935 EST on December 4, 2018, the Division 2 Mechanical Draft Cooling Tower (MDCT) fans were declared inoperable due to failure of the over speed fan brake inverter. The brakes prevent fan over speed from a design basis tornado. The MDCT fans are required to support operability of the Ultimate Heat Sink (UHS). The UHS is required to support operability of the Division 2 Emergency Equipment Cooling Water (EECW) system. The EECW system cools various safety related components, including the High Pressure Coolant Injection (HPCI) system room cooler. An unplanned HPCI inoperability occurred based on a loss of the HPCI Room Cooler. Investigation into why the Division 2 MDCT fan over speed brake inverter failed is in progress. This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(D) based on an unplanned HPCI inoperability.

"The NRC Resident Inspector has been notified."

Fermi 2 is in a 14-day LCO for inoperability of HPCI and a 72-hour LCO for UHS inoperability.

"The purpose of this notification is to retract EN 53772 made on December 4, 2018. Subsequent to the initial notification, the event and site Technical Specifications (TS) were reviewed further. An evaluation determined that TS Limiting Condition for Operation (LCO) 3.0.9 for barriers could be applied to the MDCT fan brakes. As a result of applying TS LCO 3.0.9 to the MDCT fan brakes, it was not necessary to declare the UHS inoperable. With the Division 2 UHS operable on December 4, 2018, the HPCI system was also operable. With HPCI operable, there was no event or condition that could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident under 10 CFR 50.72(b)(3)(v)(D). Therefore, EN 53772 is retracted and no Licensee Event Report (LER) under 10 CFR 50.73(a)(2)(v)(D) is required to be submitted.

"On December 19, 2018 at 10:49 am, the licensee's radiation safety officer reported a stuck shutter on a fixed gauge, found during routine maintenance. Gauge is in the open operating position; no employee or public exposures are anticipated. Gauge is attached to a vessel located several feet off the ground. Device information: source SN 8423CN, model SH-F1B, Cs-137, 100 mCi. A service company has been called to repair the gauge. Update will be sent in accordance with SA300 guidelines."

"On January 29, 2019, the licensee's Radiation Safety Officer (RSO) reported to the [Texas Department of State Health Services] that after further investigation two additional gauges were found on December 19, 2018, with shutters stuck in the open position. Open is the normal operating position. The gauges are Ohmart Vega model SH-F1B serial number 8431CN and 8443CN, both containing 100 mCi of cesium (Cs)-137. The RSO stated he discovered the additional shutter failures after reviewing reports received on January 21, 2019. The gauges are located on towers, not easily accessible, and are unlikely to cause unintended exposure. The RSO has contacted a service company and is anticipating the repairs completed to all three gauges in the next week. The RSO intends to apply grease to O-rings to prevent moisture from entering and fouling the shutter mechanism."

During a routine surveillance, oil was seen in the pool with the underwater irradiator. Testing found that the pool's conductivity was 180 micro Siemens per centimeter (æS/cm), exceeding the 20 æS/cm regulatory limit and the 100 æS/cm reportability limit. The licensee is currently filtering the water to clean up the pool and at the time of the notification had lowered the conductivity to 160 æS/cm. Additional filters are being purchased and the licensee estimates a few more days before the conductivity will be below the regulatory limit.

A leaking chiller was identified as the source of the oil. An assessment is being conducted to either repair or replace the chiller.

"Two lodine-125 breast localization seeds were placed into a patient on September 20, 2018 and removed on September 28, 2018. One seed was placed in a specimen container with the specimen, and the other seed was placed into a separate specimen container. Surgery has documentation that both seeds were sent to Pathology in separate containers; however, only one was returned to the Nuclear Medicine Department on October 4, 2018. The RSO was informed on October 5, 2018. The facility conducted searches and surveys of the Surgery, Pathology, Nuclear Medicine and Environmental Services areas, but could not locate the missing seed. Trash and regulated medical waste were also surveyed and inspected. Searches and surveys were repeated, but the seed was not found. It is believed that the seed was disposed of as regulated medical waste or in regular trash."

New York State ID: NYSDOH - 18-04

THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

"At 0910 [CST] on January 30, 2019, the Dresden Station Heater Boiler 'B' tripped while placing the station Heater Boiler 'A' in service. With colder temperatures, the density of the supply air increased and contributed to a greater quantity of air entering the Reactor Building than what was previously being supplied with heating steam in service. The Reactor Building differential pressure (DP) degraded and dropped below 0.25 inches water column vacuum. This condition represents a failure to meet Technical Specification (TS) Surveillance Requirement 3.6.4.1.1. Entry into TS 3.6.4.1 Condition A was made due to Secondary Containment becoming inoperable.

"Standby Gas Treatment System was initiated to assist with Reactor Building DP control. Reactor Building DP was restored to greater than 0.25 inches water column vacuum. TS 3.6.4.1 Condition A was exited.

"This event is being reported under 10 CFR 50.72(b)(3)(v)(C), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to ... control the release of radioactive material.'

"At 0301 [EST] on 1/31/19, with Unit 2 in Mode 1 at 100% power, the reactor was manually tripped due to icing conditions requiring the removal of 4 Circulating Water Pumps from service. The trip was not complex, with all systems responding normally post-trip. 21 CFCU [Containment Fan Cooler Unit] was inoperable prior to the event for a planned maintenance window and did not contribute to the cause of the event and did not adversely impact the plant response to the trip. An actuation of the Auxiliary Feedwater System occurred following the manual reactor trip. The reason for the Auxiliary Feed Water System auto-start was due to low level in a steam generator. Operations responded and stabilized the plant. Decay heat is being removed by the Main Steam Dumps and Auxiliary Feedwater System.

"Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported as an eight hour non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the Auxiliary Feed Water System. There was no impact on the health and safety of the public or plant personnel.

"The NRC Resident Inspector has been notified."

The icing condition was described as frazil ice.

Unit-1 reduced power to 88% because one circulating water pump was shutdown.